A petrol ether extract of the roots of Onosma paniculatum induces cell death in a caspase dependent manner

Aim of the study: Traditional Chinese medicine (TCM) has become very popular in Western countries during the last years. Zicao, a remedy of TCM, has been traditionally used to treat cancer, and, its main constituents, naphthoquinones, have been reported to possess antitumor activity (Chen et al., 2002; Papageorgiou et al., 1999). Here, we prepared extracts of different polarities of Onosma paniculatum Bur. & Franch., a plant which is amongst others used as Zicao, but, much less investigated. The extracts were analyzed concerning their growth inhibitory and apoptosis-inducing activity in various tumor cells. Materials and methods: Cell viability was measured by XTT viability and a growth inhibition assay. Effects on the cell cycle and caspase-3 were determined by flow cytometry. Results: From three different extracts, a petrol ether extract showed significant growth inhibitory effect, cell cycle influence and caspase-3 dependent induction of apoptosis which was time and dose dependent. Conclusion: To further determine the activity and mechanism of action of the petrol ether extract, we would like to isolate and identify the active principle and investigate the effects in more detail. (C) 2010 Elsevier Ireland Ltd. All rights reserved.